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From Todd Lipcon <t...@cloudera.com>
Subject Re: will upsert have bad effect on scan performace?
Date Mon, 21 May 2018 16:01:43 GMT
Hi Andy,

An upsert of a row that does not exist is exactly the same as an insert.

You can think of upsert as:

try {
  insert the row
} catch (Already Exists) {
  update the row
}

In reality, the conversion from insert to update is a bit more efficient
compared to doing the above yourself (and it's atomic). But, in terms of
performance, once the row has been inserted, it is the same as any other
row.

-Todd

On Mon, May 21, 2018 at 3:14 AM, Andy Liu <emmanual.liu@gmail.com> wrote:

> Thanks in advance.
> hi, i have used java upsert api to load data instead of insert api.
> will it have a bad effect even though these data were firstly loaded.
> i do not know compaction mechanism of kudu, will it lead to many
> compaction, thus lead to bad scan performance.
>
> Best regards.
>



-- 
Todd Lipcon
Software Engineer, Cloudera

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